Moisture Retention Seal

ABSTRACT

Various moisture retention seals are disclosed, in the contexts of canisters and corresponding closures forming packages for avoiding moisture evaporation and in retaining liquid or moisture contained in the packages.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 61/734,069, filed Dec. 6, 2012, titled “MoistureRetention Seal,” the entire contents of which are hereby incorporated byreference herein, for all purposes.

TECHNICAL FIELD

The present invention relates to fluid seals and, more particularly, toa moisture retention seal for plastic packages.

BACKGROUND ART

FIG. 1A is an exploded side view of a prior art package 100 thatincluded a cylindrically-shaped prior art canister 102 and a cup-shapedprior art closure 104, which is assembled telescopically over theopened-end of prior art canister 102. Prior art closure 104 has aninside diameter that is somewhat smaller than the outside diameter ofprior art canister 102. Prior art canister 102 and prior art closure104, when assembled as shown in dotted line, combine and cooperate toform a prior art seal 106 (FIG. 1B). Prior art canister 102 includes abottom 108, generally configured as a disk, and a sidewall 110,generally configured as a cylindrical surface, coupled to and extendingupwardly from the peripheral edge of bottom 108. Prior art canister 102includes an opened-end portion 112 defining an opening 129 for access,from the top of the canister 102, to material or objects containedtherein. Typically, prior art canister 102 is formed integrally, by, forexample, blow-molding or injection-molding of thermoplastic material.

Prior art closure 104 includes a top 114, generally configured as adisk, and a skirt 116, generally configured as an annular ring, coupledto, and depending downwardly from, the peripheral edge of top 114. Top114 defines an aperture 118 (FIG. 1B) therethrough for extractingmaterial or objects contained in the canister 102 from its opened-endportion 112 after assembly of the canister 102 and the closure 104.Often, the package 100 further includes an aperture lid 120 to close offaperture 118 of the closure 104. In one embodiment, aperture lid 120 iscoupled to the closure 104 by a living hinge 122, by which aperture lid120 pivots with respect to the closure 104 to close off aperture 118 ofthe closure 104. Typically, the closure 104 is also formed integrally,by, for example, blow-molding or injection-molding of thermoplasticmaterial. To form a seal between aperture lid 120 and closure 104,aperture lid 120 is typically snap-fitted to closure 104 in a mannerwell known to one of ordinary skill in the art. Aperture lid 120includes a lid sealing ring 132 near the outer peripheral edge on thebottom surface of aperture lid 120. Lid sealing ring 132 mates with aclosure sealing ring 134 formed on the top surface of closure 104 whenaperture lid 120 is pivoted, snap-fitted, and placed in a closedrelationship with closure 104 to form a seal.

In use of the package 100, material or objects for containment andpackaging in the package 100 are first placed in the canister 102through opening 129 (FIG. 1B) with the closure 104 removed as shown inFIG. 1A. After, the material is loaded in the canister 102, the closure104 is telescoped or fitted over and coupled to the canister 102 bysnap-fitting, thread-fitting, or other means well known to those ofordinary skill in the art. Moist or liquid materials are often packagedin the package 100. For example, moistened wipes are packaged within thepackage 100 for dispensing through aperture 118.

FIG. 1B is a partial cross-sectional side view of opened-end portion 112of the canister 102 of FIG. 1A after assembly with the canister 102showing the seal 106. FIG. 1C is a close-up view of the portion of FIG.1B shown in dotted line and identified by reference number 1C showingthe seal 106 in detail. Referring to FIGS. 1B and 1C together, theexterior surface of opened-end portion 112 of the canister 102 defines asidewall groove 124, configured generally as an annular shapedindentation circumferentially about the canister 102. Sidewall groove124 extends radially inwardly from and circumferentially about theexterior surface of the canister 102 proximate opened-end portion 112.As shown, the upper edge surface of sidewall groove 124 forms a sidewallundercut surface 126 that is beveled downwardly from its exterior to itsinterior indent.

The interior surface of skirt 116 of the closure 104 defines a skirtbead surface 128, configured generally as a peripheral flangeprotrusion, sometimes referred to as a bead, adjacent the bottom ofskirt 116. Skirt bead surface 128 extends radially inwardly from andcircumferentially about the interior surface of skirt 116 of the closure104. The canister 102 is assembled with the closure 104 by snappingskirt bead surface 128 into sidewall groove 124, whereby the closure 104is retained on the canister 102 by means of abutting contact of skirtbead surface 128 with sidewall undercut surface 126 of sidewall groove124.

In the package 100, the canister 102 and the closure 104 are furtherconfigured such that, after assembly, sidewall undercut surface 126 ofsidewall groove 124 of the canister 102 abuttingly contacts andcooperates with corresponding skirt bead surface 128 of the closure 104to form the seal 106. The seal 106 is somewhat effective at avoidingmoisture evaporation and in retaining liquid or moisture contained inthe package 100. The seal 106 slows the loss of the liquid in the formof gaseous water vapor or other volatilized gas at the seal 106 sealinginterface between the canister 102 and the closure 104.

However, in the packaging industry, plastic canisters and closures oftenare not accurately sized or may be out-of-round, so that cooperatingsurfaces of the closure and canister do not properly and accuratelyseal. In addition, the canister and closure may be manufactured bydifferent entities, and the dimensional tolerances may vary greatly. Inaddition, for threaded prior art packages, to facilitate threading ofthe closure relative to the canister, ample thread tolerances are oftenused, which results in axial and radial displacement sufficient to causemisalignment of the cooperating sealing surfaces. All of these variablesand dimensional tolerances make it difficult to ensure a good seal inprior art packages. Poor quality seals result in the loss of aninordinate amount of moistening solution added to canister/closureplastic packages, thereby requiring high initial moisture loading toavoid product dry-out during storage. High initial moisture loading addsto over-all product cost.

In the prior art, expensive elastomeric gaskets or “O” rings are oftenused to provide better seals that slow moisture loss from packages. Inaddition, well-known but expensive secondary seals, such as inductionseals or heat seals, are often used in prior art packaging to retainmoisture during distribution and in-store or user storage before productuse.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be more fully understood by referring to thefollowing Detailed Description of Specific Embodiments in conjunctionwith the Drawings, of which:

FIG. 1A is an exploded side view of a prior art package that included acylindrically-shaped prior art canister and a cup-shaped prior artclosure.

FIG. 1B is a partial cross-sectional side view of an opened-end portionof the prior art canister of FIG. 1A after assembly with the prior artclosure and showing a prior art seal.

FIG. 1C is a close-up view of the portion of FIG. 1B shown in dottedline and identified by reference number 1C showing the prior art seal indetail.

FIG. 2A is a side view of an assembled moisture retention package thatincludes a cylindrical moisture retention canister and a cup-shapedmoisture retention closure coupled to and cooperating with the moistureretention canister to provide a moisture retention seal in accordancewith the prior art.

FIG. 2B is a cross-sectional close-up side view of an opened-end portionof the moisture retention canister of FIG. 2A that shows a plurality ofpartial seals after assembly of the moisture retention closure andmoisture retention canister.

FIGS. 3-14 are cross-sectional schematic views of portions of variousmoisture retention packages and moisture retention seals includedtherein, according to various embodiments of the present invention.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

In accordance with embodiments of the present invention, methods andapparatus are disclosed for sealing a container to prevent escape ofmoisture from contents of the container.

The entire contents of: U.S. Pat. No. 8,297,461, titled “MoistureRetention Seal,” issued Oct. 30, 2012; U.S. patent application Ser. No.12/730,528, titled “Moisture Retention Seal,” filed Mar. 24, 2010 (nowabandoned); and U.S. Pat. No. 7,703,621, titled “Moisture RetentionSeal,” issued Apr. 27, 2010, are all hereby incorporated by referenceherein.

FIG. 2A is a side view of an assembled moisture retention package 200that includes a cylindrical moisture retention canister 202 and acup-shaped moisture retention closure 204 coupled to, and cooperatingwith, moisture retention canister 202 to provide a moisture retentionseal 206 (FIG. 2B), in accordance to the prior art, as described in theincorporated U.S. Pat. No. 8,297,461. In one embodiment, moistureretention canister 202 includes a bottom 208, generally configured as adisk, and a sidewall 210, generally configured as a cylindrical surface,coupled to and extending upwardly from the peripheral edge of bottom208. Moisture retention canister 202 includes an opened-end portion 212(FIG. 2B) defining an opening 229 (FIG. 2B) for access from the top ofmoisture retention canister 202 to material or objects containedtherein. In one embodiment, moisture retention canister 202 isintegrally formed and comprises blow-molded or injection-moldedthermoplastic material.

In one embodiment, moisture retention closure 204 includes a top 214,generally configured as a disk, and a skirt 216, generally configured asan annular ring or skirt, coupled to, and depending downwardly from, top214 at the peripheral edge of top 214. Top 214 defines an aperture 218(FIG. 2B) therethrough for extracting material or objects contained inmoisture retention canister 202 from opened-end portion 212 (FIG. 2B).In one embodiment, moisture retention closure 204 is integrally formedby blow-molding or injection-molding and comprises thermoplasticmaterial.

In one embodiment, moisture retention package 200 further includes anaperture lid 220 to close off aperture 218. Aperture lid 220 may becoupled to moisture retention closure 204 by a living hinge 222, bywhich aperture lid 220 pivots with respect to moisture retention closure204 to close off aperture 218 (FIG. 2B) of moisture retention closure204.

FIG. 2B is a cross-sectional close-up side view of opened-end portion212 of moisture retention canister 202 that shows various seals206A-206D after assembly of moisture retention closure 204 and moistureretention canister 202. The plurality of seals 206A-206D are partialseals that together can form a complete seal that adequately seals foranticipated uses. For example, each partial seal may have a smallunsealed area. The combination of these small unsealed areas, however,may present a relatively tortuous path for vapor to escape, thusproviding an effective seal for certain applications. In other cases,however, at least one of the seals is a full seal. In such case, theother full or partial seals simply are redundant. In either case,redundant seals can help ensure that at least one is a full seal, or atleast the combination of partial seals provides the requisite sealingcapabilities. Such use of redundant seals may increase the likelihoodthat wide error factors and tolerances of some technologies (e.g., blowmolding technology) do not eliminate sealing requirements. Unless thecontext requires otherwise or the seal is explicitly specified as apartial or full seal, seals discussed herein, with respect to FIGS. 2A-Cand FIGS. 3-35, thus may be either partial or full seals.

In the package 200 described above, with respect to FIGS. 2A-C, theclosure 204 includes a protrusion 228C that cooperates with a sidewalllip surface 226C of canister 202 to form a partial seal 206C. Severalother embodiments, which will now be described, have some similaritieswith the package 200, except that the protrusion 228C is absent or isintegral with, or otherwise indistinguishable from, the closure.

FIG. 3 is a cross-sectional view of a portion of a package 300, similarto the portion shown in FIG. 2B. However, in the embodiment shown inFIG. 3, as well as embodiments described below with respect to FIGS.4-6, a closure 302 does not include a seal-forming protrusion dependingfrom the closure 302, in contrast with the protrusion 206C discussedabove, with respect to FIG. 2. Instead, a resilient serpentine (invertical cross section) portion 304 of a canister 306 includes an endportion 308 that contacts an underside 310 of the closure 302, when thepackage 300 is closed, to form a moisture retention seal 312 between theend portion 308 of the canister 306 and the underside 310 of the closure302. The contact between the end portion 308 and the underside 310 ofthe closure 302 may be a point (as seen in cross-section) or at severalcontiguous or discontiguous points. As the closure 302 is progressivelydepressed beyond a point where the underside 310 initially makes contactwith the end portion 308, the serpentine portion 304 resilientlydeforms, therefore urging the end portion 308 against the underside 310with progressively greater force and, therefore, creating aprogressively tighter seal. Force exerted by the closure 302 on the endportion 308 of the canister 306 is indicated by an arrow 314.

When the closure 302 is not in contact with the serpentine portion 304of the canister 306, the serpentine portion 304 and, in particular, theend portion 308, is in a rest position. However, when the closure 302comes in contact with the serpentine portion 304, the force 314 exertedon the end portion 308 may deflect the end portion 308 by a deflectionangle 316 to a deflected position shown in dashed line at 318. Thedeflection angle 316 is less than about 90°. Of course, the end portion308 or another part of the serpentine portion 304 remains in contactwith the underside 310 of the closure 302 to provide a moistureretention seal. Space in FIG. 3 between the dashed portion 318 and theunderside 310 of the closure 302 is shown merely for clarity.

The closure 302 includes an inside diameter at a locking skirt beadsurface 320 that is somewhat smaller than the canister 306 outsidediameter at corresponding complementary sidewall undercut surface 322.For clarity, a space is shown in FIG. 3 between the skirt bead surface320 and the undercut surface 322. However, in the embodiment, absent anexternal force, while the package 300 is closed, the skirt bead surface320 contacts the undercut surface 322 to create a second seal and toprovide mechanical resistance to opening the package 300. Thismechanical resistance can, however, be overcome by a typical user byexerting moderate force by hand.

Optionally, the serpentine portion 304 may be configured to make contactat one or more locations, exemplified by locations 324 and 326, with avertical inside circumferential surface 328 of the closure 302. Again,for clarity, a space is shown in FIG. 3 between the convex portions(undulations) 330 and 332 of the canister 306 and the vertical insidecircumferential surface 328. However, in some embodiments, while thepackage 300 is closed, the convex portions 330 and 332 contact thevertical inside circumferential surface 328.

FIG. 4 is a cross-sectional view of a portion of another package 700,similar to the portion shown in FIG. 3. The package 700 includes acanister 702 and a closure 704. The canister 702 includes a serpentineportion 706 and an end portion 708, and the closure 704 includes aprotrusion 710 depending from an underside 712 of the closure 704.However, this protrusion 710 does not contact, or form a moistureretention seal with, the end portion 708, the serpentine portion 706 orany other portion of the canister 702.

A moisture retention seal is formed by circumferential contact betweenat least one inside diameter portion of the closure 704 and at least oneoutside diameter portion of the canister 702. For example, in oneembodiment, one or more outwardly directed portions of the serpentineportion 706, exemplified by portions 714 and 716, contact respectiveportions of an inside wall 718 of the closure 704 to form one or moremoisture retention seals at locations 720 and 722.

Optionally or alternatively, an inside diameter at skirt bead surface724 is somewhat smaller than the canister 702 outside diameter at acorresponding sidewall undercut surface 726. While the package 700 isclosed, the skirt bead surface 724 contacts the undercut surface 726 tocreate another moisture retention seal and to provide mechanicalresistance to opening the package 700. However, for clarity, spaces areshown in FIG. 4 between the skirt bead surface 724 and the undercutsurface 726, as well as locations 720 and 722. Arrows 728 and 730indicate directions of force exerted by the closure 704 and the canister702, respectively.

Furthermore, optionally, an upward-facing portion 732 of the serpentineportion 706 may be configured to contact, and make a moisture retentionseal with, a downward-facing portion 734 of the closure 704. Again, forclarity, a space is shown in FIG. 4 between the upward-facing portion732 of the serpentine portion 706 and the downward-facing portion 734 ofthe closure 704.

FIGS. 5 and 6 are cross-sectional views of a portion of another package900, similar to the portion shown in FIG. 4. The package 900 includes acanister 902 and a closure 904. FIG. 9 shows the closure 904 not fullyengaged with the canister 902, whereas FIG. 6 shows the closure 904fully engaged with the canister 902. For clarity, spaces are shown inFIG. 6 where contact is actually made between portions of the canister902 and the closure 904.

To attach the closure 904 to the canister 902, the closure 904 islowered, as indicated by arrow 906, until a skirt bead surface 908,which is somewhat smaller inside diameter than the canister 902 outsidediameter at a corresponding sidewall undercut surface 910, contacts theundercut surface 910. When closed, the skirt bead surface 908 and thesidewall undercut surface 910 may form a moisture retention seal.

The canister 902 includes a bendable annular flap 912. The flap 912 maybe resilient and/or another portion 914 of the canister 902 may beresilient to facilitate bending of the flap 912 from a rest position(shown in FIG. 5), by a deflection angle 915 (shown in FIG. 6) to adeflected position (shown in FIG. 6). As the closure 904 is lowered, aslanted underside portion 916 of the closure 904 contacts the flap 912,such as initially at an end 918 of the flap 912, and bends the flap 912from the flap 912 orientation shown in FIG. 5 to the flap 912orientation shown in FIG. 6. In the orientation shown in FIG. 6, theflap 912 takes on a frustoconical shape. Once the closure 904 is fullyengaged with the canister 902, at least a portion of the flap 912remains in contact, and forms a moisture retention seal 1000, with theslanted underside portion 916 of the closure 904.

FIG. 7 is a cross-sectional view of a portion of another package 1100,which includes a canister 1102 and a closure 1104. In some embodiments,the canister 1102 and the closure 1104 are fabricated of respectivematerials and/or with respective dimensions (such as thicknesses) thatmake the closure 1104 more ridged than the canister 1102, or at least afinger 1112 of the canister 1102. The closure includes a protrusion 1106extending downward from an underside of the closure 1104. The protrusion1106 defines an annular hollow area 1108 between the protrusion 1106 andan inside circumference of a downward extending portion 1110 of theclosure 1104. The finger 1112 fits into the hollow area 1108, when theclosure 1104 is attached to the canister 1102. The finger 1112 and theprotrusion 1106 are configured such that the finger 1112 is resilientlydisplaced outward, as indicated by arrow 1114, as the closure 1104 isattached to the canister 1102. Thus, while the closure 1104 is attachedto the canister 1102, the finger 1112 is urged by its resilienceagainst, and therefor forms a moisture retention seal 1115 with, theprotrusion 1106. The protrusion 1106 may include a chamfer 1116, and anend 1118 of the finger 1112 may be rounded, to facilitate inserting thefinger 1112 into the hollow 1108 and bypassing the protrusion 1106.

Any suitable mechanism may be used to secure the closure 1104 to thecanister. For example, an inside diameter at skirt bead surface 1120 maybe somewhat smaller than the canister 1102 outside diameter at acorresponding sidewall undercut surface 1122. While the package 1100 isclosed, the resilience of the finger 1112 may urge the closure 1104upward, thereby urging the skirt bead surface 1120 against an outwardskirt bead 1124 of the canister 1102, thereby forming another moistureretention seal 1126. Lateral overlap between the two skirt beads 1120and 1124 provides mechanical resistance to opening the package 1100.

FIG. 8 is a cross-sectional view of a portion of another package 1500.The package 1500 includes a canister 1502 and a closure 1504. Thecanister 1502 includes an upwardly-directed wall 1506 having an end1508. The closure 1504 includes a downwardly-directed protrusion 1510.At least a portion 1512 of the protrusion 1510 is resilient such that,when the closure 1504 is brought down to attach to the canister 1502, anend 1514 of the protrusion 1510 is resiliently deflected radiallyoutward by the end 1508 of the wall 1506, as indicated by arrow 1516.Contact between the end 1508 of the wall 1506 and the end portion 1514of the protrusion 1510 form a moisture retention seal 1520.

In some embodiments, the canister 1502 and the closure 1504 arefabricated of respective materials and/or with respective dimensions(such as thicknesses) that make the closure 1504, or at least theportion 1512 of the protrusion 1510, more flexible than the canister1502.

Although not shown in FIG. 8, the package 1500 may include any suitablestructure to secure the closure 1504 to the canister 1502, such as theskirt bead and the undercut surface described above, with respect toFIG. 7.

Embodiments described below, with respect to FIGS. 9-13, involve ahorizontal, or at least not entirely vertical, contact to form amoisture retention seal.

FIG. 9 is a cross-sectional view of a portion of another package 1700.The package 1700 includes a canister 1702 and a closure 1704. In someembodiments, the canister 1702 and the closure 1704 are fabricated ofrespective materials and/or with respective dimensions (such asthicknesses) that make canister 1702, or at least a finger 1706 of thecanister 1702, more flexible than the closure 1704. In some embodiments,the canister 1702, or at least a finger 1706 of the canister 1702, andthe closure 1704 may be of approximately equal flexibility. The closureincludes a protrusion 1706 extending downward from an underside of theclosure 1704. The protrusion 1706 may be sloped so its bottom defines alarger diameter than its top.

A finger 1707 and the protrusion 1706 are configured such that thefinger 1707 is resiliently displaced radially inward, as indicated byarrow 1708, as the closure 1704 is attached to the canister 1702. Thus,while the closure 1704 is attached to the canister 1702, the finger 1707is urged by its resilience against, and therefor forms a moistureretention seal with, the protrusion 1706. The protrusion 1706 mayinclude a chamfer, and an end 1710 of the finger 1704 may be rounded, tofacilitate the finger 1704 bypassing the protrusion 1706.

Any suitable mechanism may be used to secure the closure 1704 to thecanister 1072. For example, an inside diameter at skirt bead surface1712 may be somewhat smaller than the canister 1702 outside diameter ata corresponding sidewall undercut surface 1714. While the package 1700is closed, the protrusion 1706 urges the finger 1708 inward, asindicated by arrows 1716. The resilient finger 1707 may urge theprotrusion 1706 upward, thereby urging the skirt bead surface 1712against an outward skirt bead 1718 of the canister 1702, thereby forminganother moisture retention seal. Lateral overlap between the two skirtbeads 1712 and 1718 provides mechanical resistance to opening thepackage 1700.

For clarity, a space is shown in FIG. 9 between the two skirt beads 1712and 1718 and between the finger 1707 and the protrusion 1706. However,in the embodiment, absent an external force, while the package 1700 isclosed, these spaces are closed by respective members, as described.

FIG. 10 is a cross-sectional view of a portion of another package 1900,similar to the portion shown in FIG. 9. The package 1900 includes acanister 1902 and a closure 1904. In some embodiments, the canister 1902and the closure 1904 are fabricated of respective materials and/or withrespective dimensions (such as thicknesses) that make the closure 1904,or at least a dependent annular protrusion 1906 of the closure 1904,more flexible than the canister 1902, or at least a finger 1908 of thecanister 1902. In some embodiments, the closure 1904, or at least thedependent annular protrusion 1906 of the closure 1904, and the canister1902, or at least a finger 1908 of the canister 1902, are approximatelyequally flexible. The protrusion 1906 is resilient and extends downwardfrom an underside of the closure 1904. A diameter of an end 1910 of thefinger 1908 is smaller, and generally concentric with, a diameter of anend 1912 of the protrusion 1906. In some embodiments, a surface 1914 ofthe finger 1908 that faces the protrusion 1906 is curved, so the top ofthe finger 1908 defines a smaller diameter than the bottom of the finger1908.

The finger 1908 and the protrusion 1906 are configured such that theprotrusion 1906 is resiliently displaced radially outward, as indicatedby arrow 1916, as the closure 1904 is attached to the canister 1902. Inthese embodiments, the finger 1908 is not displaced radially inward, orit is not significantly displaced radially inward, by the protrusion1906. Contact between the finger 1908 and the protrusion 1906 forms amoisture retention seal.

In some embodiments, the protrusion 1906 is more resilient than finger1908. In other embodiments, the finger 1908 is more resilient than theprotrusion 1906. In yet other embodiments, the protrusion 1906 and thefinger 1908 are approximately equally resilience.

In some embodiments, the finger 1908 and the protrusion 1906 areconfigured such that the finger 1908 is resiliently displaced radiallyinward, as indicated by dashed arrow 1917, as the closure 1904 isattached to the canister 1902. Contact between the finger 1908 and theprotrusion 1906 forms a moisture retention seal.

In some embodiments, the finger 1908 and the protrusion 1906 areconfigured such that the finger 1908 is resiliently displaced radiallyinward, as indicated by dashed arrow 1917, and the protrusion 1906 isresiliently displaced radially outward, as indicated by arrow 1916, asthe closure 1904 is attached to the canister 1902. Contact between thefinger 1908 and the protrusion 1906 forms a moisture retention seal.

Any suitable mechanism may be used to secure the closure 1904 to thecanister 1902. For example, an inside diameter at skirt bead surface1918 may be somewhat smaller than the canister 1902 outside diameter ata corresponding sidewall undercut surface 1920.

FIG. 11 is a cross-sectional view of a portion of another package 2000,similar to the portion shown in FIG. 7. The package 2000 includes acanister 2002 and a closure 2004. The closure 2004 includes an annularprotrusion 2006 extending downward from an underside of the closure2004. The protrusion 2006 defines an annular hollow area 2008 betweenthe protrusion 2006 and an inside circumference of a downward extendingportion 2010 of the closure 2004.

The canister 2002 includes an annular finger 2012 having a radiallyoutwardly-curved upper end. The finger 2012 fits into the hollow area2008, when the closure 2004 is attached to the canister 2002. The finger2012 and the protrusion 2006 are configured such that the finger 2012 isresiliently displaced radially outward, as indicated by arrows 2014, asthe closure 2004 is attached to the canister 2002. Thus, while theclosure 2004 is attached to the canister 2002, the finger 2012 is urgedby its resilience against, and therefor forms a moisture retention sealwith, the protrusion 2006. The protrusion 2006 may include a concaveportion 2016 sized and shaped to complement the outwardly-curved upperend of the finger 2012.

In some embodiments, the canister 2002, or at least the annular finger2012, and the closure 2004, or at least the protrusion 2006, arefabricated of respective materials and/or with respective dimensions(such as thicknesses) that make flexibility of the closure 2004, or atleast the protrusion 2006, approximately equal to flexibility of thecanister 2002, or at least the annular finger 2012. In otherembodiments, the closure 2004, or at least the protrusion 2006, may bemore or less flexible than the canister 2002, or at least the annularfinger 2012.

Any suitable mechanism may be used to secure the closure 2004 to thecanister 2002. For example, an inside diameter at a skirt bead surface2018 may be somewhat smaller than the canister 2002 outside diameter ata corresponding sidewall undercut surface 2020.

Embodiments described below, with respect to FIGS. 12-14, involve ahorizontal, or at least not entirely vertical, resilient compression orother resilient deformation of a member to create a force that urges twomember into contact so as to form a moisture retention seal.

FIGS. 12 and 13 are cross-sectional views of a portion of anotherpackage 2200, similar to the portion shown in FIG. 7. The package 2200includes a canister 2202 and a closure 2204. The closure 2204 includesan annular wall 2006 extending downward from an underside of the closure2204. The wall 2206 defines an annular hollow area 2208 between the wall2206 and an inside circumference of a downward extending portion 2210 ofthe closure 2204.

The canister 2202 includes an annular serpentine portion 2212 having aradially outwardly-curved upper end 2214. The wall 2206 defines agenerally radially outwardly facing concave curved portion 2216, shapedto complement the curved end 2214 of the serpentine portion 2212. Thus,when the closure 2204 is brought down to be attached to the canister2202, the concave portion 2216 of the wall contacts the curved portion2214 of the serpentine portion 2212 and resiliently forces it radiallyoutward, as indicated by arrows 2218, so the serpentine portion 2212aligns with the hollow area 2208. The serpentine portion 2212resiliently bends generally radially outward, as indicated by curvedarrow 2313 (FIG. 13). Further downward movement of the closure 2204causes the serpentine portion 2212 to enter the hollow area 2208, asshown in FIG. 13. However, resilience of the serpentine portion 2212causes it to remain in contact with, and ride along, an inside walldefining the hollow area 2208. This contact forms a moisture retentionseal.

Although not shown in FIGS. 12 and 13, the package 2200 may include anysuitable structure to secure the closure 2204 to the canister 2202, suchas the skirt bead and the undercut surface described above, with respectto FIG. 7.

FIG. 14 is a cross-sectional view of a portion of another package 2600.The package 2600 includes a canister 2602 and a closure 2604. Theclosure 2604 includes two concentric annular walls 2606 and 2608extending downward from an underside of the closure 2604. The walls 2606and 2608 define an annular hollow area 2610 between the walls 2606 and2608.

The canister 2602 includes an upwardly-oriented annular serpentineportion 2612 having a radially outwardly-curved upper end 2614. Thewalls 2606 and 2608 are disposed and configured so the annular hollowarea 2610 vertically aligns with the upwardly-oriented annularserpentine portion 2612, when the closure 2604 is aligned with, but notattached to, the canister 2602, as shown in FIG. 14. When the closure2604 is brought down to be attached to the canister 2602, as indicatedby arrow 2616, the upper end 2614 of the serpentine portion 2612 entersthe hollow area 2610. However, the width 2618 of the serpentine portion2612 is greater than the width of the hollow area 2610. (For clarity,FIG. 26 shows the serpentine portion 2612 compressed, thus having awidth 2618 less than the width of the hollow area 2610.) Thus, as theserpentine portion 2612 enters the hollow area 2610, the walls 2606 and2608 contact the serpentine portion 2612, forming moister retentionseals at the contact points and compressing the serpentine portion 2612from both sides, as indicated by arrows 2620 and 2622. As shown in FIG.14, undulations in the serpentine portion 2610 need not all be of thesame size; however, in some embodiments, these undulations are all thesame size.

In some embodiments, the serpentine portion 2612 is long enough to reachthe underside 2624 of the closure 2604, when the closure 2604 is fully,or nearly fully, attached to the canister 2602. In these cases, contactbetween the upper end 2614 of the serpentine portion 2612 and theunderside 2624 of the closure 2604 forms another moisture seal.

Although not shown in FIG. 26, the package 2600 may include any suitablestructure to secure the closure 2604 to the canister 2602, such as theskirt bead and the undercut surface described above, with respect toFIG. 7.

Packages, including canisters, closures and members thereof, may bemanufactured using conventional techniques and conventional materials,such as blow-molding or injection-molding of thermoplastic materials.Any embodiment describe herein may include a closable and sealable lidin the closure. Embodiments described herein may be used to store anddispense moist towelettes, liquids, powders and other products.

While the invention is described through the above-described exemplaryembodiments, modifications to, and variations of, the illustratedembodiments may be made without departing from the inventive conceptsdisclosed herein. Furthermore, disclosed aspects, or portions of theseaspects, may be combined in ways not listed above and/or not explicitlyclaimed.

What is claimed is:
 1. A package, comprising: a closure having aninterior surface; and a canister having a flexible top portion incontact with the interior surface of the closure, the interior surfaceof the closure normally applying a generally downward contact force toat least part of the flexible top portion to form a top seal between theclosure and the canister, the interior surface of the canisterdeflecting the at least part of the flexible top portion generallydownward from a rest position; wherein: the at least part of theflexible top portion of the canister is in the rest position when not incontact with the closure; and the interior surface of the closuredeflects the at least part of the flexible top portion of the canisterby a deflection angle from the rest position when in contact with thecanister, the deflection angle being less than about ninety degrees. 2.A package according to claim 1, wherein the interior surface of theclosure is generally planar.
 3. A package according to claim 1, whereinthe interior surface of the closure is generally frustoconical.
 4. Apackage according to claim 1, wherein the flexible top portion of thecanister is in contact with the interior surface of the closure at otherthan a protrusion extending from the interior surface of the closure. 5.A package according to claim 1, wherein the flexible top portion of thecanister has, in vertical cross section, a serpentine shape.
 6. Apackage according to claim 1, wherein the flexible top portion of thecanister has a generally annular shape when in the rest position and agenerally frustoconical shape when deflected from the rest position. 7.A package according to claim 1, wherein the closure includes a lockingskirt and the canister has a complimentary locking feature, the lockingskirt and the complementary locking feature cooperating to secure theclosure to the canister and provide a second seal between the closureand the canister.
 8. A package according to claim 1, wherein: theflexible top portion of the canister has a generally serpentine verticalcross section defining at least one radially outwardly convex portion;the closure defines a generally vertical inside circumferential wall;and the flexible top portion and the closure are configured such that,when the closure is when in contact with the canister, the at least oneradially outwardly convex portion contacts the generally vertical insidecircumferential wall of the closure, thereby forming at least a secondseal between the closure and the canister.